U.S. patent number 5,510,125 [Application Number 08/378,253] was granted by the patent office on 1996-04-23 for process for selective removal of sugar from beverages.
This patent grant is currently assigned to Bucher-Guyer AG Maschinenfabrik. Invention is credited to Walter Gresch.
United States Patent |
5,510,125 |
Gresch |
April 23, 1996 |
Process for selective removal of sugar from beverages
Abstract
To remove selectively particularly sugar from nonalcoholic or
alcoholic beverages, first the sugar is either carried away in the
permeate in a membrane separation unit (2) by suitable choice of
membrane (4) or is retained in the retentate. Afterward, the sugar
is removed from the permeate or from the retentate with the help of
a device (5) for substance removal or substance conversion. Next
the substances remaining in the permeate or in the retentate after
the removal of the sugar are fed back into the process or the final
product. With the process according to the invention, a high
selectivity and an improvement in quality of the final product with
high economic efficiency of the unit is achieved (FIG. 1).
Inventors: |
Gresch; Walter (Niederweningen,
CH) |
Assignee: |
Bucher-Guyer AG Maschinenfabrik
(Niederweningen, CH)
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Family
ID: |
27173168 |
Appl.
No.: |
08/378,253 |
Filed: |
January 24, 1995 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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291848 |
Aug 17, 1994 |
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460330 |
Dec 28, 1989 |
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Foreign Application Priority Data
Current U.S.
Class: |
426/11; 426/13;
426/493; 426/16; 426/425; 426/486; 426/487; 426/12; 426/15;
426/14 |
Current CPC
Class: |
C12H
1/16 (20130101); C13B 20/165 (20130101); C13B
35/08 (20130101); A23L 2/74 (20130101); C12H
3/04 (20190201); B01D 61/243 (20130101); B01D
61/246 (20130101); B01D 61/58 (20130101); B01D
61/145 (20130101); B01D 61/025 (20130101) |
Current International
Class: |
A23L
2/74 (20060101); A23L 2/70 (20060101); C12H
1/00 (20060101); C12G 3/00 (20060101); C12G
3/08 (20060101); C13J 1/00 (20060101); C13J
1/08 (20060101); C13D 3/00 (20060101); C13D
3/16 (20060101); C12H 1/16 (20060101); B01D
61/58 (20060101); B01D 61/24 (20060101); A23L
001/015 () |
Field of
Search: |
;426/11,12,13,14,15,16,425,487,493,486 |
References Cited
[Referenced By]
U.S. Patent Documents
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4626437 |
December 1986 |
Schobinger et al. |
4806366 |
February 1989 |
Dick et al. |
|
Foreign Patent Documents
Primary Examiner: Pratt; Helen
Attorney, Agent or Firm: Jaskiewicz; Edmund M.
Parent Case Text
This is a continuation of application Ser. No. 08/291,848 filed on
Aug. 17, 1994, now abandoned, which was a continuation of
application Ser. No. 07/460,330 filed Dec. 28, 1989, now abandoned.
Claims
I claim:
1. Process for selective removal of non-volatile substances,
consisting of one or more of the non-volatile substances selected
from the group consisting of sugar, acids and substances causing
bad taste, from beverages or sugar-containing solutions, by
membrane separation processes comprising the steps of subjecting
the beverage or sugar-containing solution to a membrane separation
process to separate a non-volatile substance therefrom to produce a
permeate having the substance therein separated from the beverage
and a retentate having a reduced quantity of said substance
retained therein, subsequently removing at least a portion of the
retained said substance from the retentate or the separated
substance from the permeate, at least partially circulating the
permeate from the membrane separation process in a permeate
circuit, one of removing or converting the substance in the
permeate circulating in the permeate circuit to achieve high
selectivity of substance removal, and subsequently feeding back
into the retentate at least a portion of the permeate with said
separated substance removed therefrom.
2. Process according to claim 1 wherein the removal of the
substance from the permeate or from the retentate of membrane
separation unit (2) is performed by chemical precipitations.
3. Process according to claim 1 wherein, to remove the substance
from the permeate or from the retentate, chromatographic processes
are used.
4. Process according to claim 1 wherein, to remove the substance
from the permeate or from the retentate, absorption and absorption
processes are used.
5. Process according to claim 1 wherein, to remove the substance
from the permeate or from the retentate, sheet filters are
used.
6. Process according to claim 1 wherein the removal of the
substance from the permeate or from the retentate is performed by
liquid/liquid extraction.
7. Process according to claim 1, wherein the removal of the
substance from the permeate or the retentate is performed by
substance conversion comprising fermentation.
8. Process according to claim 1 wherein the removal of the
substance from the permeate or from the retentate is performed by
substance conversion by enzymatic processes.
9. Process according to claim 1, wherein, after substance removal
or substance conversion, the permeate is partially fed back into
the permeate beyond a membrane separation unit (2) for the membrane
separation process.
10. Process according to claim 1 wherein there is placed in
permeate circuit (3) a fermenter (12) in which sugars contained in
the permeate are converted into alcohol, the alcohol is at least
partially removed in a subsequent dealcoholization device (14) or
by extraction by addition of at least another beverage and the
desugarized and dealcoholized or alcoholic permeate is again fed
back into permeate circuit (3) beyond the fermenter (12).
11. Process according to claim 10 wherein the permeate contains
flavoring substances, extracts, salts and acids, and to produce an
alcohol-free or reduced-alcohol beverage, the sugars contained in
the retentate are converted into alcohol by fermentation, the
alcohol is at least partially removed by a subsequent
dealcoholization and afterward the flavoring substances, extracts,
salts, and acids contained in the permeate are again fed back to
the retentate after fermentation and dealcoholization.
12. Process for selective removal of non-volatile substances,
consisting of one or more of the non-volatile substances selected
from the group consisting of sugar, acids and substances causing
bad taste, from beverages or sugar-containing solutions by membrane
separation processes comprising the steps of subjecting the
beverage or sugar-containing solution to a membrane separation
process to separate a non-volatile substance therefrom to produce a
permeate having the substance therein separated from the beverage
and a retentate having a reduced quantity of said substance
retained therein, subsequently removing at least a portion of the
retained said substance from the retentate or the separated
substance from the permeate, at least partially circulating the
permeate from the membrane separation process in a permeate
circuit, one of removing or converting the substance in the
permeate circulating in the permeate circuit to achieve high
selectivity of substance removal, and subsequently feeding back
into the permeate at least a portion of the permeate with said
separated substance removed therefrom.
13. Process according to claim 12 wherein the removal of the
substance from the permeate or from the retentate of membrane
separation unit (2) is performed by chemical precipitations.
14. Process according to claim 12 wherein, to remove the substance
from the permeate or from the retentate, chromatographic processes
are used.
15. Process according to claim 12 wherein, to remove the substance
from the permeate or from the retentate, absorption and absorption
processes are used.
16. Process according to claim 12 wherein, to remove the substance
from the permeate or from the retentate, sheet filters are
used.
17. Process according to claim 12 wherein the removal of the
substance from the permeate or from the retentate is performed by
liquid/liquid extraction.
18. Process according to claim 12 wherein the removal of the
substance from the permeate or the retentate is performed by
substance conversion comprising fermentation.
19. Process according to claim 12 wherein the removal of the
substance from the permeate or from the retentate is performed by
substance conversion by enzymatic processes.
20. Process according to claim 12, wherein, after substance removal
or substance conversion, the permeate is partially fed back into
the permeate beyond a membrane separation unit (2) for the membrane
separation process.
21. Process according to claim 12 wherein there is placed in
permeate circuit (3) a fermenter (12) in which sugars contained in
the permeate are converted into alcohol, the alcohol is at least
partially removed in a subsequent dealcoholization device (14) or
by extraction by addition of at least another beverage and the
desugarized and dealcoholized or alcoholic permeate is again fed
back into permeate circuit (3) beyond the fermenter (12).
22. Process according to claim 51 wherein the permeate contains
flavoring substances, extracts, salts and acids, and to produce an
alcohol-free or reduced-alcohol beverage, the sugars contained in
the retentate are converted into alcohol by fermentation, the
alcohol is at least partially removed by a subsequent
dealcoholization and afterward the flavoring substances, extracts,
salts, and acids contained in the permeate are again fed back to
the retentate after fermentation and dealcoholization.
Description
FIELD OF THE INVENTION
The invention relates to a process for selective removal of
nonvolatile substances, such as sugar and/or acid and/or substances
that cause a bad taste, from nonalcoholic or alcoholic beverages by
membrane separation processes.
DESCRIPTION OF THE RELATED ART
The main application of the invention is the desugarization of
largely alcohol-free beverages and in addition also the
deacidification and general refining of alcohol-free as well as of
alcoholic beverages (e.g., wine, beer) made of natural products
such as fruits, berries, grapes, vegetables, grains, soy and
products of livestock husbandry, e.g., milk. By the removal of bad
taste and acids is mainly meant general refining. The
above-mentioned substances to be removed are nonvolatile, Parallel
with the removal of said nonvolatile substances, volatile
substances, e.g., imperfect flavoring, can also be removed if
desired. The portion of all the substances to be removed amounts
here to less than 25%. Desugarization, and to a more limited extent
also the deacidification and refining of beverages, are used to
comply with the need of consumers for fewer calories, less
sweetness, suitability for diabetics, less acid, etc.
Various chemical processes are already known for desugarization.
DE-PS 22 32 093 relates to extracting sugar from molasses according
to the ion exclusion resin process. Here, the sugar-containing
molasses is conveyed through a column filled with ion-exchange
resin, separating the sugar. Another process for extracting sucrose
from molasses is known from U.S. Pat. No. 3,997,357. The
sugar-containing molasses is mixed with lime and the sucrose is
extracted by subsequent filtering. Finally, EP-OS 0 047 518 shows a
process in which the sucrose is extracted by contact of the
sugar-containing mixture with adsorbers.
These known chemical processes yield an insufficient quality for
beverage purposes, since the desugarization is not selective
enough. The object of these processes is above all the extraction
of sugar, for which purpose selectivity is of secondary
importance.
The use of membrane separation processes is known in the art for
dealcoholization of beverages. Here, the volatile alcohol
substances are carried away through the membrane into the permeate.
But these known dealcoholization processes cannot easily be
transferred to the removal of sugar from beverages because of the
considerably higher molecular weight and the nonvolatile compounds
such as sugar, acid, taste substances and are also not suited for
this purpose. For this reason, dealcoholization by membrane
processes must use membranes with very low separation limits. With
the use of reverse osmosis and reverse osmosis combined with
dialysis, it is in the range of pure reverse osmosis, e.g., 92-99%
salt retention, relative to 0.5% aqueous NaCl solution, 40 bars
transmembrane pressure and 20.degree. C. process temperature.
Further, the separation of alcohol from the permeate circuit is
performed by so-called liquid-volatile separation processes, e.g.,
distillation, thus nonvolatile components, such as sugar, acid,
taste substances cannot be separated nonselectively.
SUMMARY OF THE INVENTION
Thus the object of the invention is to avoid the drawbacks
mentioned and to provide a process of the type mentioned above that
guarantees an improvement in the quality of the final product with
greater economic efficiency.
This object is achieved according to the invention in that, after
performing the membrane separation process, the separated substance
is removed or converted from the permeate or the retained substance
is removed or converted from the retentate by physical, chemical or
biotechnological processes and subsequently the substances
remaining after removal or conversion are at least partially fed
back into the process or to the final product.
The performance of the unit is increased if the membrane separation
process consists of a combination of dialysis and reverse osmosis
and the separation is performed by increased transmembrane pressure
and by a difference in concentration.
Advantageously, the separation area of the membrane separation unit
is in the boundary area between the low-molecular and the
macromolecular or in the boundary area between reverse osmosis and
ultrafiltration.
According to another embodiment feature of the invention, the
membrane separation unit operates according to the ultrafiltration
process with a separation limit of a maximum of 5,000 daltons.
To remove the substance from the permeate or from the retentate of
the membrane separation unit, know physical processes such as
chromatographic processes, sheet filters, taste-modifying cellar
treatment processes and liquid/liquid extraction processes as well
as chemical processes such as known chemical precipitation
processes, among other things, for use in the separation of
nonvolatile substances, can be used advantageously.
For substance removal by substance conversion, biotechnological
processes such as fermentation and enzymatic processes are
advantageously used.
According to another feature of the invention, the permeate of the
membrane separation unit is circulated at least partially and the
device for substance removal or substance conversion is placed in
the permeate circuit.
The efficiency of the unit is improved by feeding the permeate,
after substance removal or substance conversion, at least partially
back into the retentate beyond the membrane separation unit.
To produce a more or less sweet, dealcoholized or slightly
alcoholic beverage, according to one embodiment of the invention, a
fermenter is placed in the permeate circuit of the membrane
separation unit, a fermenter in which the sugar contained in the
permeate is converted into alcohol, the alcohol is at least
partially removed preferably in a subsequent dealcoholization
device or by extraction by adding a second beverage and the
desugarized and dealcoholized or slightly alcoholic permeate is fed
back again into the permeate circuit beyond the fermenter.
To prevent too much flavoring substance from diffusing into the
permeate, according to another embodiment of the invention there is
placed, upstream from the membrane separation unit, a separation
device which also operates according to the membrane process and
into which the raw juice is introduced and conveyed as retentate to
the retentate side of the membrane separation unit, and the
permeate containing the flavoring substances is introduced into the
retentate beyond the membrane separation unit.
Suitably, the separation limit of the upstream separation unit is
less than the separation limit of the membrane separation unit, but
is also in the boundary area of reverse osmosis and
ultrafiltration.
In another embodiment of the invention, the substance removal or
substance conversion is performed on the retentate side beyond the
membrane separation unit. Here, the membrane of the membrane
separation unit is suitably selected so that the permeate contains
mainly the substances desired in the final product and the
retentate contains the substances to be removed or converted.
In addition to an application for beverages, the process can also
be used for isolation and concentration of sugar during extraction
of sugar from sugar-containing solutions, especially in connection
with a sugar solution obtained by enzymatic decomposition of
cellulose, e.g., from wood.
In an especially advantageous embodiment of the invention for the
production of an alcohol-free or reduced-alcohol beverage, the
sugar contained in the retentate of the membrane separation unit is
converted into alcohol by fermentation, the alcohol is at least
partially removed by a subsequent dealcoholization and afterwards
the flavoring substances, extracts, salts, acids, etc. contained in
the permeate are again fed to the retentate after the fermentation
and dealcoholization.
The advantages achieved with the invention consist particularly in
that, by combining the membrane separation process and subsequent
substance removal or substance conversion, a high selectivity and
thus quality is achieved. The beverage desugarized and/or
deacidified according to the process of the invention exhibits a
high quality and is largely matched to special consumer
requirements. The process according to the invention also makes
possible a refining of the beverage by the removal of bad taste,
which can arise from the use of bad raw material, unfavorable
processing or too long a storage. The desugarization and
modification of the ratio of sugar to acid makes possible a further
adaptation to specific consumer requirements, e.g., by producing
special, thirst-quenching beverages such as apple juice with little
sugar and an increased acid/sugar ratio. Further, depending on the
separation area of the membrane, a product with a high content of
coloring substances, extractive substances, tanning substances,
etc. can be achieved. In addition to taste, as a side effect the
flavor can also be positively influenced, e.g. by new, useful
flavor substances arising during fermentation or by removing
bad-flavor by, e.g., adsorption and absorption processes.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained in further detail in the following
description and in the drawing, which represents several
embodiments. There are shown in:
FIG. 1, a diagrammatic representation of the unit according to the
invention with substance removal or substance conversion on the
permeate side,
FIG. 2, the unit according to FIG. 1 with desugarization by
fermentation as well as a device for flavoring recovery and
FIG. 3, another embodiment with substance removal or substance
conversion on the retentate side.
The raw juice, from which the sugar is to be removed, is fed
according to FIG. 1 by a pipe 1 to a membrane separation unit 2.
Membrane separation unit 2 consists of a combined dialysis/reverse
osmosis unit, in which the permeate flows countercurrent to the
retentate. The unit is equipped with a special module that makes
possible a permeate circuit 3 countercurrent to the retentate
stream. But the use of an ultrafiltration unit with the same
special module is also possible. The preferred separation area of
membrane separation unit 2 lies in the boundary area between the
low molecular and the macromolecular, i.e., in the boundary area
between reverse osmosis and ultrafiltration, whose maximum
separation limit is 5,000 daltons. In this area, colorants are
still kept back. Further, macromolecular substances, e.g., extract
substances, polyphenols, etc., pass through membrane 4 of membrane
separation unit 2 to a greatly reduced extent.
A device 5 for selective substance removal or substance conversion
is placed in permeate circuit 3. The substances to be removed or
converted such as, e.g., sugar, acid, bad taste, alcohol from
sugar, salts from sugar or acid are removed by a pipe 6. The
permeate flowing countercurrent to the retentate is circulated and
is again introduced into membrane separation unit 2 on the lower
permeate side. The beverage freed from the undesired substance
leaves membrane separation unit 2 by pipe 7 as retentate. After
removal of the substance, part of the permeate is fed back by a
pipe 8 again into the retentate beyond membrane separation unit
2.
In device 5, the sugar, acid or bad taste substance contained in
the permeate is removed by the use of physical, chemical or
biotechnological processes or is converted into beverage-compatible
substances. Because membrane 4 of membrane separation unit 2 is
selected in the separation limit so that primarily the substances
to be removed diffuse and additionally a selective substance
removal process is used on the permeate side, overall a high
selectivity is produced compared to the individual steps. With the
use of individual steps there exists the danger that too much is
removed.
Device 5 for selective substance removal can, for example, operate
in the known way according to the precipitation process. In
particular for the removal of sugar, the known Stefan process or
similar processes can be used. To remove acids, the known cellar
treatment methods are suited, as well as enzymatic processes.
Further, chromatographic processes, such as, e.g., the ion
exclusion process, can be used for the removal of sugar. To remove
bad taste, adsorption and absorption processes, e.g., by activated
carbon, are suited. Further, sheet filters can be used, and the
property of the filter beds is used not only to filter purely
mechanically but also to agglutinate colloids. In principle, all
taste-changing or refining cellar treatment processes and means can
be used for substance removal. Here the effect with the processes
according to the invention is milder, compared with conventional
processes, since only the permeate is treated.
Finally, the substance removal can also be performed by
liquid/liquid extraction. For this purpose, permeate circuit 3 is
fed mineral water and/or at least another beverage as well as
possible additives by a pipe 9. Both liquids are enriched with the
substance to be removed, e.g., sugar, in permeate circuit 3 and
withdrawn by a pipe 10 as another beverage that now contains the
sugar removed from the first beverage. More additives can be mixed
with the other beverage by a pipe 11. The first, desugarized
beverage leaves membrane separation unit 2 as retentate by pipe 7.
To intensify the substance exchange, suitable extraction equipment
in known embodiments can be used.
Instead of the substance removal, a substance conversion can also
be performed in device 5. For this purpose, biotechnological
processes already common in the beverage sector are especially
suited. According to FIG. 2, a fermenter 12 that converts the sugar
contained in the permeate into alcohol is placed in permeate
circuit 3. If the production of a slightly alcoholic beverage is
desired, the alcohol is left in the permeate. Since at most an
amount of alcohol is produced as there is sugar in the permeate, a
more or less sweet alcoholic beverage results, as desired. In this
way, an addition of foreign solvents, as is often necessary after a
dealcoholization with conventional processes, is superfluous to
arrive again at a desired beverage body. If, in contrast, the
alcohol is to be reduced, the permeate can be completely or
partially dealcoholized by the use of known processes. For this
purpose, the fermented permeate enriched with alcohol is fed by a
pipe 13 to a dealcoholization unit 14, in which the alcohol is
removed. The dealcoholized permeate is again introduced by a pipe
15 into permeate circuit 3 beyond fermenter 12. The desugarized and
dealcoholized permeate is introduced, together with water,
extracts, acid, salts, flavoring residues including new flavoring
substances, from the fermentation into the lower permeate side of
membrane separation unit 2 and a part of it is fed back into the
retentate by pipe 8.
In permeate circuit 3 there can be provided a deacidification
process 16 in which acid is removed from the permeate in addition
to, or as an alternative to, desugarization.
Instead of dealcoholization unit 14, similar to the already
described desugarization by liquid/liquid extraction, the alcohol
can be extracted from the permeate by adding a second beverage and
thus a second, alcoholic beverage can be obtained.
As another measure for substance conversion, enzymatic processes
can also be performed in device 5. Among these processes there is,
for example, the so-called Navinginase, which is used and has
become known to debitterize grapefruit juice. Since the enzymes
practically are not lost on the permeate side, enzymatic processes
simultaneously mean a cost saving.
To compensate for the water that diffuses into the permeate
together with the substances to be removed through membrane 4 of
membrane separation unit 2, beverage dilution water is fed by a
pipe 17 to the raw juice before it enters membrane separation unit
2. Another compensation for the water results from the fact that
part of the desugarized or converted permeate is fed back into the
retentate by pipe 8.
The unit according to FIG. 2 can additionally be equipped with a
flavoring-recovery device 18. The latter consists of a separation
device 19 upstream from membrane separation unit 2, a separation
device that preferably operates also according to the membrane
separation process to avoid a quality-degrading heat load of the
beverage. The raw juice is introduced into separation unit 19 by
pipe 1 and reaches membrane separation unit 2 by a pipe 20 as
retentate. Consisting mainly of flavoring substances and some
sugar, the permeate of separation device 19 is fed back into the
retentate by a pipe 21 beyond membrane separation unit 2. In this
way it is avoided that, e.g., during desugarization and/or
deacidification, too many flavoring substances diffuse through
membrane 4 of membrane separation unit 2 into the permeate and,
during treatment, are degraded or lost on the permeate side. Such a
device is placed if, for reasons of performance, work is done at
relatively high pressures or an extremely high quality is to be
achieved. A high concentration and high separation selectivity are
not necessary, since the removed flavoring is immediately fed back
again into the retentate stream. But this is true provided that the
juice is not to be concentrated subsequently. Separation device 19
preferably has a somewhat lower separation limit than membrane
separation unit 2, but it lies preferably also in the transition
area between reverse osmosis and ultrafiltration.
FIG. 3 represents an embodiment of the invention in which device 5
is placed for selective substance removal or substance conversion
in the retentate stream beyond membrane separation unit 2. By
suitable choice of membrane 4, mainly the substances to be removed
remain in the retentate that leaves membrane separation unit 2 by
pipe 7. For a desugarization, the separation limit of membrane 4
preferably lies in the transition area between reverse osmosis and
ultrafiltration. The permeate that flows away by pipe 22, contains
mainly the substances desired in the final product. This has the
advantage that the beverage undergoes no changes as a result of the
treatment methods for substance removal or substance conversion.
For the substance removal or substance conversion occurring on the
retentate side, the same is true as described in the embodiments
according to FIGS. 1 and 2.
If, in the embodiment according to FIG. 3, the substance conversion
to desugarize a certain beverage is performed by fermentation,
i.e., by the use of fermenter 12, then in this way a beverage with
slight alcohol content, little sugar and a high content of
flavoring, extracts, acids and salts of the original beverage can
be produced. The sugar retained in the retentate by suitable choice
of membrane 4 is converted into alcohol in fermenter 12. By a
subsequent dealcoholization, the alcohol content is at least
reduced. The flavoring losses occurring in doing so are slight,
since the flavoring substances, extracts, salts, acids and, to a
limited extent, sugar contained in the original beverage already
diffuse beforehand together with the water into the permeate, which
is again fed to the retentate after the desugarization and
dealcoholization and, together with the retentate, forms the new
alcohol-reduced or alcohol-free, desugarized beverage.
The possibility also exists of combining the unit according to FIG.
3 with the unit according to FIG. 1 or 2.
* * * * *